I Have 8 Wires What Wire Goes To What Terminal

Most t-stats are self explanatory. The letter typically represents the color unless the person who wired it originally was a hack and used the wrong  wire. If your system is just for heat then wire  red to rh, white to w,

if your system has air conditioning the red is to rh (with a jumper from rh to rc), white to w, yellow to y, green to g blue may be used to go from rc at the furnace to rc at the t-stat in which case you wont need a jumper from rh to rc. The others should be spares unless your system has a two stage gas valve in which case you'll have r1, r2 w1, w2. Can't tell not knowing but this should give you the basics.  if you do it wrong, you may blow the fuse on the control board at the furnace.typically 3 amp (purple) YOU CAN GET AT ANY AUTO PART STORE.
Hope this was helpful.